Cn compounds



United States Patent 3,410,809 CN COMPOUNDS Iral B. Johns, Marblehead,Mass., assignor to Monsanto Research Corporation, St. Louis, Mo., acorporation of Delaware No Drawing. Continuation-impart of applicationSer. No. 323,110, Nov. 12, 1963. This application May 28, 1965, Ser. No.459,874

12 Claims. (Cl. 260-2) This application is a continuation-in-part ofco-pending application S.N. 323,110, filed Nov. 12, 1963, now abandoned.

This invention relates to new chemicals and methods for their synthesis,and more particularly, provides novel compounds in which an element ofGroups III to V of the Periodic Table is joined successively to C and N,and methods of making the same.

The cyano (nitrile) group, -CEN, as a substituent of organic compoundscan be converted by various methods, such as acid or base catalysis, tothe divalent linking unit, C=N-. The products of such conversion arepolymers. These may be oligomers (low molecular weight polymers) such astriazines:

where R is an organic radical. They may also be higher molecular weightpolymers. Organic nitriles including monofunctional nitriles can formpolymers, which :are assigned the structure where R is an organicradical and n is an integer with a value of 4 or more, which may or maynot be cyclic.

It is an object of this invention to provide new chemical compounds inwhich an organo-substituted inorganic nonmetallic element of GroupsIII-V of the Periodic Table is joined successively to C and N.

A particular object of this invention is the provision of neworganophosphorus compounds.

Another object of this invention is the provision of new triazineshaving organo-substituted inorganic non-metal lic ring substituents.

Another object is the provision of new polymeric materials.

Still another object is the provision of a novel method of convertingthe cyanides of organo-substituted inorganic non-metallic elements ofGroups III to V of the Periodic Table into oligomers and high polymers.

These and other objects will become evident upon consideration of thefollowing specification and claims.

It has now been found that cyanides of organophosphorus compounds can behomopolymerized and can be copolymerized with cyanides of organoboronand organosilicon compounds, forming polymers in which the repeatingunit has the same empirical formula as the monomer, and the cyano groupforms the linking bond.

The stated conversion can be effected in either of two ways.

One method, provided by this invention, is a catalytic reaction,consisting of contacting the reaction mixturecomprising anorganophosphorus cyanide with an ionic catalyst. The catalyzedconversion can be carried out at atmospheric pressures.

A second method, provided by this invention, consists in heating thereaction mixture comprising an organophos- 3,410,809 Patented Nov. 12,1968 phorus cyanide under elevated pressure, such as pres sures above1000 kg./sq. cm. The high pressure conversion will take place in theabsence of a catalyst.

Surprisingly, the stated high pressure condensations proceed without anyconsiderable decomposition of the starting materials. Whentricyanophosphine is heated under pressure, it loses nearly all its Ncontent to give a solid containing C and P. Metallic cyanides reactsimilarly: anyhydrous lithium cyanide at 400 C. and 25,000 kg./sq. cm.decomposes suddenly, yielding C and N; and mercuric cyanide likewise,decomposes at elevated temperatures and pressures to a black solid fromwhich elemental mercury can be removed in high vacuum on heating. Thepresently employed organo-substituted phosphorus, silicon and boroncyanides, however, instead condense without loss of elements, to formoligomers and higher polymers, in which the repeating unit has the sameempirical formula as the monomer.

Copolymerization with the organophosporus cyanides is a method ofproducing polymers from cyanides which resist homopolymerization. Thus,the organoboron cyanides, which are particularly strongly coordinated inthe monomeric state, are not converted to solid polymers on exposure toheat and pressure. However, polymers in eluding organoboryl substituentsare found to be obtained under such conditions when the organo-boroncyanides are copolymerized with the organophosphorus cyanides.

In studies of the condensation of organic nitriles to oligomers such astriazines under elevated temperatures and pressures, especially atreasonably accessible pressures, below 10,000 atmopheres, it has usuallybeen found necessary to catalyze the reaction, using anionic catalystssuch as ammonia or amine, for example. With the presentorgano-substituted boron, silicon and phosphorus cyanides, on the otherhand, no catalyst is found necessary to produce the condensation uponapplication of elevated temperatures and pressures, and indeed, use of abasic catalyst has been found unfavorable to the high pressurepolymerization.

The products of the methods of this invention are organophosphorushomopolymers and copolymers in which organo-substituted elementsselected from the group consisting of P, B and Si are joinedsuccessively to C and N. The term, polymer, is used herein to designatehomoand copolymers, including both oligomers and higher polymers. Anoligomer is a low molecular weight polymer, which is formed of repeatingunits but which has a low molecular weight, below 1500, say. Thepresently provided oligomers include triazines, such asphosphinotriazines, of the formula where each R (each of R R R and soforth) is an organic radical. Higher molecular weight polymers, whichvmay be designated poly(nitrilomethylidynes) (N=(|J- repeating units) arealso produced, such as phosphorus-substituted polymers of the formula[RIIIL'RZI n where R, and R are organic radicals and n is an integergreater than 3.

The uses of the presently provided novel products are various, dependingupon their nature. The oligomeric products such as triazines in somecases are fluids over a wide temperature range, and may be used asfunctional fluids, for heat or power transfer, lubrication or the like.Thermal stability is a characteristic of the presently pro videdproducts. The high polymers generally neither soften nor decompose attemperatures up to 300400 C., and can be sintered to provide heat-stablerigid materials of construction. The presently provided triazines softenand plasticize the polymers, providing readily moldable compositionsfrom which shaped structural forms can be produced, or which can beapplied to surfaces such as glass to provide an adherent opaquepaint-like coating; the waxy mixtures of these oligomers and higherpolymers can also be employed as dielectric materials, and so forth.

Referring now in more detail to the practice of this invention, thepresently useful monomeric starting materials include phosphoruscyanides of the formula where X is a chalkogen element having an atomicweight below 35, a and b are the integers 1 or 2 and the sum of a and bis 3, and c is the integer 0 or 1. The stated phosphorus cyanidesproduce polymeric products having substituents of the formula in whichR, X, a, b and c are as defined above.

Cyanides of organo-substituted inorganic non-metallic elements which canbe copolymerized with the stated organophosphorus cyanides includecyanoboranes of the formula )a' )b in which a and b are integers with avalue of at least 1, and the sum of a and b is 3. This producespolymeric products including as substituents groups of the formula h' UM' where a and b are defined as just stated. Also susceptible tocopolymerization by the present process are cyanosilanes of the formulam nsnczm u in which a" and b" are integers with a value of at least 1and the sum of a" and b" is 4. This produces polymeric productsincluding as substituents groups of the formula (R)asl(=X) :N)b"

in which a" and b are defined as just stated.

In the stated formulas, each R may be the same or different and is aradical consisting of elements selected from the class consisting of C,H and 0, said 0 being ether oxygen, linking adjoining C atoms, free ofaliphatic (olefinic or acetylenic, carbon-to-carbon) unsaturation andcontaining up to 12 carbon atoms and up to 1 oxygen atom. In general,the presently employed cyano compounds are known in the art or may beprepared by methods analogous to those known in the art; reference maybe made in this connection, for example, to my copending concurrentlyfiled application S.N. 459,931 for the (phenoxyphenyl)phenylphosphinecyanides. Preferably R is an aromatic radical bonded by a benzene ringcarbon atom to the inorganic element, such as phenyl or phenoxyphenyl.

The phosphorus cyanides useful as starting materials for the practice ofthe present invention include cyanodiorganophosphines of the formula(R)2P(CEN), dicyanoorganophosphines of the formula RP(CEN)2 and thecorresponding oxides and sulfides, of the general formula I s1 (CEN)bwhere X is S or O, a and b are each 1 or 2, and their sum is 3,

4 Exemplary of presently useful cyanodiorganophosphines aredihydrocarbyl and bis(hydrocarbyloxyhydrocarbyl) phosphines such ascyano diethylphosphine, cyanodimethylphosphine,cyanodiisopropylphosphine, cyanodibutylphosphine,cyanodiphenylphosphine,

cyano bis (p-phenoxyphenyl) phosphine, cyanodihexylphosphine,cyanodiheptylphosphine,

cyano bis Z-ethyl-hexyl phosphine, cyano dioctylphosphine,

cyanobis (m-butoxyphenyl phosphine, cyanoethylmethylphosphine,butylcyanoisopropylphosphine, cyanoethyl Z-ethylhexyl phosphine,cyanodinaphthylphosphine, cyanornethylphenylphosphine,

cyano (phenoxyphenyl phenylphosphine, cyanodi-p-tolylphosphine,

cyanobis (p-ethylphenyl) phosphine, cyanobis(isopropylphenyl phosphine,

cy anobis isopropoxyphenyl phosphine, cyanodibenzylphosphine,benzylcyanoethylphosphine, cyanodicyclopentylphosphine,

cy anodicyclohexylphosphine,

cyanobis cyclohexylcyclohexyl phosphine, cyanoisopropylphenylphosphine,benzylcyanophenylphosphine, cyanodicyclop ropylphosphine,

cyanobis 2-phenylethyl phosphine, cyanobis Z-phenoxyethyl phosphine,

cy a'noethyl (p-ethylbenzyl phosphine, cyanocyclohexylphenylphosphine,cyanocyclohexyl (phenoxyphenyl phosphine, cy anomethylZ-methylcyclopentyl phosphine, cyanobis (p-biphenylyl phosphine,cyanodifurfurylphosphine and so forth.

The dicyanoorganophosphines which may be converted to higher molecularweight products in accordance with this invention includedicyanohydrocarbylphosphines anddicyano(hydrocarbyloxyhydrocarbyl)phosphines such asdicyanophenylphosphine, dicyano(phenoxyphenyl phosphine,dicyanoethylphosphine, dicyanobutylphosphine,dicyanocyclohexylphosphine, dicyanocyclopentylphosphine,dicyanobenzylphosphine, dicyano-p-tolylphosphine,dicyano-p-butoxyphenylphosphine, dicyano 2-ethylhexyl phosphine, dicyanop-isopropoxybenzyl phosphine, dicyano (p-isopropylphenyl phosphine,dicyanooctylphosphine,

dicyano furyl phosphine,

dicyano o-ethylbenzyl phosphine, dicyano 2- p-butylphenoxy] ethylphosphine, dicyanoisobutylphosphine, dicyanopentylphosphine,dicyanoxylylphosphine,

dicyano (phenoxyhexyl) phosphine, dicyanohexylphosphine and the like.

Exemplary of the presently useful cyanoorganophosphine chalkogenides arecyanodiphenylphosphine sulfide,

cyanobis (phenoxyphenyl phosphine sulfide, cyanodiphenylphosphine oxide,

cyanobis (phenoxyphenyl phosphine oxide, cyanodiethylphosphine sulfide,cyanodimethylphosphine sulfide,

cyanodicyclohexylphosphine sulfide, cyano(phenoxyphenyl)phenylphosphinesulfide, cyanodibenzylphosphine sulfide, cyanodi-p-tolylphosphinesulfide,

cyanobis 2-ethylhexyl phosphine oxide, cyanobenzylethylphosphinesulfide, cyano(p-isopropylphenyl)butylphosphine sulfide,cyanooctylphenylphosphine oxide, cyanobis(2-ethylbenzyl)phosphine oxide,cyanoisobutyloctylphosphine sulfide, cyanodipentylphosphine sulfide,cyanocyclohexylphenylphosphine sulfide, cyanodixylylphosphine oxide,cyanoethylmethylphosphine sulfide, cyanobis(3,3-dimethylbutylphenyl)phosphine sulfide, cyanodiindenylphosphine sulfide,cyanodifurylphosphine oxide, cyanodibiphenylylphosphine sulfide; anddicyanophenylphosphine sulfide, dicyano(phenoxyphenyl) phosphinesulfide, dicyanophenylphosphine oxide,

dicyano (phenoxyphenyl)phosphine oxide, dicyanomethylphosphine sulfide,dicyano-p-t-butylphenylphosphine sulfide, dicyanocyclohexylphosphinesulfide, dicyanobutylphosphine oxide, dicyano(2-ethylbenzyl)phosphineoxide, dicyano Z-methylcyclopentyl phosphine sulfide,dicyano(cyclohexyl)phosphine sulfide, dicyano(furfuryl)phosphine oxideand the like.

In general, aromatic radicals in which a ring carbon atom is linked tothe phophorus atom are preferred for thermal stability of the products,and particularly organic radicals having no CH or CH radicals. Themonocyanophosphorus compounds, and of the monocyanophosphines, themonocyanophosphine sulfides are especially preferred monomers.

The presently useful organoboron cyanides include, for example,cyanodiphenylborane, cyano(phenoxyphenyl)- phenylborane,cyanoethylmethylborane, cyanomethylphenylborane,cyanobis(phenoxyphenyl)borane, cyanodip-tolylborane,cyanodicyclohexylborane, cyanodicyclopentylborane, cyanodibenzylborane,cyanobis(2 phenylethyl)b0rane, cyanobis(2-phenoxyethyl)borane,cyanodibutylborane, cyanodimethylborane, cyanodiisopropylborane,cyano(Z-methylcyclopentyl)pentylborane, cyanodiisoctylborane,cyanodicyclohexylborane, cyanodifurylborane, cyanodiindenylborane,dicyanophenylborane, dicyano(phenoxyphenyl)borane, dicyanomethylborane,and the like.

The organosilane cyanides which can be converted to higher molecularweight products by the method of this invention includedicyanodiorganosilanes such as diphenyldicyanosilane, (phenoxyphenyl)phenyldicyanosilane, bis phenoxyphenyl dicyanosilane,diethyldicyanosilane, dibutyldicyanosilane, dioctyldicyanosilane,bis(ethoxyphenyl)dicyanosi1ane, ethyl(2-ethylhexyl) dicyanosilane,methylphenyldicyanosilane, methyl(phenoxyphenyl)dicyanosilane,benzyldicyanophenylsilane, di-p-biphenylyldicyanosilane and the like,and cyanotriorganosilanes and tricyanoorganosilanes such ascyanotriphenylsilane, cyanotris(phenoxypheny1)silane,cyanotrimethylsilane, cyanotriethylsilane,cyanotris(2-ethoxyethyl)silane, cyanotri-tbutylsilane,cyanotriisopropylsilane, cyano(ethoxyethyl)- diethylsilane,cyanotri-p-tolylsilane, cyanotri-2,4-xylylsilane, cyanobis(phenoxyphenyl)phenylsilane, cyanotrinaphthylsilane,cyanotridodecylsilane, cyanotri-p-biphenylylsilane,cyanodi(biphenylyl)phenylsilane, tricyanomethylsilane,tricyanophenylsilane, tricyano(phenoxyphenyl)silane,tricyano(ip-t-butylphenyl)silane, tricyano(p-isopr-opoxyphenyl)silane,tricyanocyclohexylsilane, tricyanobenzylsilane and so forth.

The presently provided polymers may be generally designatedpolynitrilomethylidynes; specifically, they are poly(phosphino-,poly(phosphinothioyl-, and poly(phosphinylnitrilomethylidynes) which mayor may not include boryland silylnitrilomethylidyne groups. The trimericspecies of the products are triazines, viz., phosphino-,phosphinothioyl-, and phosphinyltriazines, which may or may not includeboryl and silyl substituents. The other polymeric species may also becyclic, but this is not established. The various phosphorus-containing,silyl and boryl substituents of the polymeric products will be of theformulas stated above, that is,

and (R),,"Si(CN) The infrared spectra of polymers obtained frompolycyano compounds in accordance with this invention are free of theabsorption characteristic of cyano groups, so that the indicatedpossible residual CN groups are considered as also linked into thepolymeric structures as nitrilomethylidyne groups. The presentlycontemplated copolymers of the phosphorus cyanides with the boron,silicon or boron and silicon cyanides are characterized by inclusion ofat least. sufiicient of each of a phosphorus-containing substituent anda substituent selected from a boryl and a silyl substituent todifferentiate the copolymers significantly from the respectivehomopolymers of the cyanides; in general, 595 mole percent of thesubstituents will be a phosphorus-containing substituent of theabove-stated formula.

Conversion conditions The present conversion of organo-substituted GroupIII to V element cyanides can be accomplished under varying conditions.Various pressures and temperatures can be used, and catalysts andsolvents may or may not be present in the reaction mixture.

Essentially, effecting the reaction requires maintaining theorgano-substituted inorganic Group III-V element cyanide either incontact with a catalyst or under elevated pressures until conversion topolymer has occurred.

Either the individual cyanides or mixtures of the presently usefulorgano-substituted inorganic cyanide reactants may be employed in thepresent procedures. The organophosphorus cyanides can be homopolymerizedor can be copolymerized either with each other or with the organoboronand organosilicon cyanides. The organophosphorus cyanide content will beat least 5 mole-percent of the total organo-substituted inorganic GroupIII-V element cyanide content of the reaction mixture, and may begreater, up to mole-percent in the presently provided copolymers of Pwith B and Si, and molepercent in the homopolymers.

Temperatures used may vary from down to where the reaction mixture isbarely liquid up to any temperature below decomposition temperatures ofthe reaction mixture components. The rapidity of the reaction will varywith the reactants chosen, and in some cases the reaction may beexothermic and require cooling and/or diluents to moderate its violence,while other reactants may not undergo significant conversion until afterhours at elevated temperatures. Suitable temperatures for carrying outthe conversion are generally in the range of about 25 to C., in the caseof the catalyzed polymerization. In high pressure polymerizations inaccordance with this invention, the temperature and pressure requiredfor the conversion are usually interdependent. In general, the higherthe pressure, the lower the temperature required to initiate thepolymerization, and the higher the temperature, the lower the pressure.Preferably, temperatures above about 200 C. are employed in the highpressure polymerizations conducted in the absence of catalyst. Theconversion is accelerated by elevating the temperature, and frequentlyfor practicable reaction rates at reasonably low pressures, temperaturesof 250 C. and above may be used.

The pressures at which the present polymerization is conducted may rangefrom subatmospheric pressures, down to say about 0.5 mm. Hg, tosuperatmospheric pressures, up to above about 1000 kg./sq. cm. andpreferably, above about 5000 kg./ sq. cm. The catalyzed polymerizationmethod of the present invention can be carried out at the lowerpressures, below 1000 kg./sq. cm. if desired. Since this embodiment ofthe present invention can be conducted at about atmospheric pressure,the use of such pressure is generally advantageous in this connection.To produce polymerization of the organo-substituted inorganic cyanidesat practicable rates in the absence of a catalyst, elevated pressuresmust be employed, at least above about 1000 kg./ sq. cm. and preferablyabove about 5000 kg./sq. cm. Higher pressures, ranging up to 20,000kg./sq. cm. or more, can be used if desired.

Catalysis of the present polymerization is produced by contacting theorgano-substituted inorganic cyanide with an ionic catalyst, and moreparticularly, with anhydrous lithium cyanide. The amount of lithiumcyanide used to produce the polymerization may be merely a catalyticamount, which may be very small, such as 0.01 mole per mole of themonomer, say, though greater amounts may also be used if desired. Whilethe use of LiCN catalyst at about atmospheric pressure has been foundeffective in producing the polymeric products of this invention, andespecially the polymers of the organosubstituted phosphorus compounds,use of an ionic catalyst such as diethylamine at elevated pressures,above about 5000 log/sq, cm., has actually been found disadvantageous.Since the exposure to elevated pressure alone produces the desiredpolymerization, the presence of catalysts in practicing the highpressure embodiment of the present invention is unnecessary in any case.

The ongano-substituted inorganic cyanides may be heated and catalyzed orcompressed to effect their condensation alone or in the presence ofsolvents. Use of solvents is generally desirable.

Useful solvents include hydrocarbon solvents such as benzene, tolueneand xylene, hexane, pentane, and cyclohexane; oxygenated solventsincluding others such as diethyl ether, dioxane, and the dimethyl etherof ethylene glycol; amides such as dimethylformamide, dimethylacetamideand so forth; nitriles such as acetonitrile, tertiary amine bases suchas pyridine and triethylamine; sulfoxides such as dimethyl sulfoxide;and so forth.

The time required to accomplish the reaction depends on functionalfactors such as the reactivity of the reactant, the temperature andpressure of reaction and so forth. Reaction rates and times of reactionmay vary considerably also depending on the details of apparatus andother operational conditions. By suitable arrangements, con.- tinuousprocedures may be employed, or batch type operations.

On completion of the reaction, the polymer formed in the reaction isseparated by conventional methods such as precipitation, vaporization,distillation, extraction and the like.

The invention is illustrated but not limited by the following examples.

Example 1 This example illustrates conversion of an organophosphinedicyanide to a higher molecular weight product of the same empiricalformula.

The bomb used for the polymerization is one useful for the pressurerange up to 10,000 kg./sq. cm. It is 0.75 inch I.D., 3 inch O.D., 4 inchlong, and provided with Bridgman leakproof closures. Heating isaccomplished by means of an electrically heated jacket around the bomb.A dial gauge meaures relative motion of the upper piston with respect tothe lower plug, giving a measure of the volume changes duringcompression and chemical reaction. The bomb and plugs are made of redhard tool steel, heat treated for maximum toughness, with a Rockwell Chardness number of 5354.

A solution of 2.5 grams (g.) of dicyanophenylphosphine in 2.5 g. ofbenzene in a lead tube is put in the cylinder and surrounded by oil.Pressure in the cylinder is raised to 7600 kg./sq. cm. (kilograms persquare centimeter) and the cylinder is heated to 260 C. No ther'rnaleffect is observed and no change in volume. After cooling, the leadcapsule is removed and cleaned. Its weight has not changed.

The contents of the capsule are black and on filtration yield a veryfine, black powdery solid. The powder is washed with benzene andpetroleum ether and vacuum dried at C. The product corresponds to 25%'of the phosphine used, and has the same empirical formula as thestarting compound. The infrared spectrum shows the complete absence of-CEN groups.

When the reaction is repeated using 5 1g. of dicyanophenylphosphine and12 g. of benzene directly in the steel cylinder, without the use of acollapsible tube, with the charge maintained at 265275 C. and 7600leg/sq. cm. for 33 minutes, again, while no thermal effect is observed,a 20% yield of the same black ploymer is obtained.

Example 2 This example illustrates preparation of polymers from a diorganophosphine cyanide.

Using the same apparatus and technique as in the above experiment, acharge consisting of a solution of 7 g. of diphenylcyanophosphine in 12g. of benzene is compressed in the steel cylinder (without use of acollapsible container to 7700 kg/sq. cm. and heated to 265 C. for onehour. The reus-lting black liquid yield 0.1 g. of a dark brown solidhaving nearly the same nitrogen and phosphorus content as the startingcompound, and melting at 200-210 C.

When the preparation is repeated using 7 g. of diphenylcyanophosphinewithout solvent in a collapsible lead tube and subjecting it to 7600atmospheres at 285 C. for two hours, there is a steady decrease involume, and complete condensation occurs, yielding a hard black solid.

When this condensation product is exhaustively extracted with benzene ina Soxhlet apparatus, it yields a benzene-insoluble fraction (55%) and abenzene-soluble fraction (45%). The benzene-soluble solid is the cyclictrimer, tris(diphenylphosphino) triazine, of the formula It has ameasured average molecular weight of 714 in benzene compared with 633calculated for the cyclic trimer.

The benzene-insoluble fraction is a higher molecular weight compoundconsisting of repeating units of the same empricial formula as themonomer.

The condensation products of the cyanophosphines are more stable towardoxidation and hydrolysis than are the cyanophosphin-es themselves: thepolymers are stable in moist air while the cyano compounds hydrolyze,producing HCN.

Example 3 This example illustrates preparation of polymers from anotheronganophosphorus compound.

Cyanodiphenylphosphine sulfide is prepared by charging a reaction flaskWith 63 g. of cyanodiphenylphosphine (0.3 mole), and adding 51 g. (0.3mole) of phosphorous thiochloride, under nitrogen. The mixture is heatedat C. until evolution of phosphorus trichloride has ceased. The productvacuum-distilled from the resulting reaction mass at 149-151 C. at 0.25millimeter (ITIIIL) Hg pressure is cyanodiphenylphosphine sulfide.Characteristics of the liquid product are n 1.6414, 11 1.2023. Onstanding, the compound solidifies to a white solid, M. 50.0- 50.2 C.

High pressure condensation of the cyanodiphenylphosphine sulfide iscarried out at 7600 kg/sq. cm. and about 250 C. The reaction is followedby observing the decrease in volume. Less than 13 minutes are requiredfor complete reaction. The hard, black, brittle product becomes toughand resinous at about 100 C. and melts to a black viscous liquid athigher temperatures.

Analysis of the product, without further treatment, gives:

Calcd for C H NPS: C, 64.18; H, 4.14; N, 5.76; P, 12.75; S, 13.18. Foundpercent: C, 64.33; H, 4.35; N, 5.75; P, 12.53; S, 13.11.

The agreement shows that no decomposition occurs during thecondensation.

Extraction of the product with benzene yields 49% of a black, insolubleresidue analyzing 13.3% P, 6.5% N, and 13.9% S. The infrared spectrumshows the complete disappearance of the CEN group at 2180 cmf Thisinsoluble polymer does not melt or decompose even at 360 C. and appearsto be completely heat-stable, but softens at 310-320 C. On compressionand heating at 4000 kg./sq. cm. and 300 C., it sinters to a hard,coherent cylinder having a density of 1.2 grams per cubic centimeter.

The benzene-soluble part is recovered by precipitation with petroleumether and drying in vacuum. It is 51% of the original and analyzes12.99% P, 4.24% N and 12.98% S. This fraction behaves like a tough,adhesive wax. It softens like a wax on gentle heating and slowly meltsat below 150 C. to a very viscous black liquid. This liquid is notvolatile and is heat-stable to temperatures above 300 C.

Some of this soluble fraction is melted, poured into a collapsible leadtube, and returned to the high pressure bomb, where it is heated againto 280 C. at 7600 kg./ sq. cm. for 1 hour. The melting behavior is againobserved and found to be unchanged.

The benzene-soluble fraction has an observed molecular weight of 700compared with the value of 729 calculated for the trimer. The analysisand molecular weight are consistent with identification of the productas tris(diphenylphosphinothioyl) triazine, with the structure II H s N sThe infrared spectrum of the trimer shows the disappearance of the C Nband at 2180 cmr and the appearance of a C N band.

When diethylamine is used as catalyst for conversion ofcyanodiphenylphosphine sulfide to polymer at elevated pressure, theproduct obtained at 255 C. and 7600 kg./ sq. cm., containing thetrimeric triazine product, includes less high polymer, with onlyinsoluble in benzene.

Example 4 This example illustrates preparation of a polymer from anorganoboron cyanide by copolymerization with an organophosphorouscyanide.

Equal molar quantities of cyanodiphenylphosphine and cyanodiphenylboraneare mixed, forming a homogeneous liquid which is sealed in a collapsiblelead capsule and compressed as described above at 7600 kg./sq. cm. and285-300 C. A slow change in volume occurs. After 7% hours, the bomb iscooled and the capsule recovered. Its weight is the same as before theexperiment. The product is a nearly black solid.

A larger sample, 13.5 g. of the equimolar mixture, is

compressed directly in the steel bomb without use of the collapsibletube, in the presence of an internal thermocouple, at 7600 kg./sq. cm.at 300 C. The thermocouple record shows no thermal effect afteroperating conditions have been established. The dial gauge shows a slowbut continued volume decrease over a period of 5 hours.

The product is recovered as a black solid. It is stable in air.Extraction with benzene removes some browncolored material, which is notunreacted cyanodiphenylborane: it does not yieldaminoethyldiphenylborinate on reaction with ethanolamine.

The black condensation product, after thorough extraction with benzene,and vacuum drying, analyzes as follows.

Calcd for C H N PB: C, 77.83; H, 5.02; N. 6.98; P, 7.33; B, 2.83. Foundpercent: C, 68.68; H, 4.78; N, 5.85; P, 9.19; B, 1.68.

This product is completely stable at 360 C.

Example 5 This example illustrates another preparation of a polymericproduct from an organoboron cyanide, by copolymerization with acyano-substituted organophosphine sulfide.

A mixture of 4.2 g. of cyanodiphenylphosphine sulfide (M.P. 502 C.) and3.3 g. of cyanodiphenylborane (M.P. 119125 C.) (both colorlesscompounds) is melted to form a viscous, deep-red liquid that remainsliquid on cooling to room temperature, crystallizing only after a halfhour. The liquid is poured into a collapsible lead tube, which is sealedand pressurized under oil in the high pressure apparatus. No volumechange can be observed as the pressure is maintained at 7600 kg./sq. cm.and 260300 C. for 1.5 hours. The sample is found to have polymerized toa hard, black mass.

Example 6 This example illustrates preparation of a higher molecularweight product from an organosilicon cyanide.

The preparation of dicyanodiphenylsilane described by McBride (J. Org.Chem. 24 (1959) 2029) is followed, producing a water-white liquid whichboils at 122 C./ 0.24 mm. (12 1.5625 and d 1.1067). The calculated molarrefraction shows it to be the normal cyano compound although theinfrared spectrum indicates that it might contain both cyano andisocyano groups. The compound can be separated by vapor phasechromatography into two fractions whose infrared spectra show a markeddifference in relative intensity of the bands at 2180 and 2260 cmfExposure of an equimolar mixture of this clear colorless liquiddicyanodiphenylsilane preparation with cyanodiphenylphosphine sulfide to7600 kg./sq. cm. pressure and 253 C. yields a black, soft, adherent wax.The infrared spectrum shows disappearance of the -CEN groups.

Example 7 This example illustrates conversion of an organophosphomscyanide to a polymer at atmospheric pressure us ing an ionic catalyst.

A -ml., single-necked round-bottomed flask fitted with reflux condenserwith CaCl drying tube atop is charged with chlorodiphenylphosphine oxide(23.6 g. 0.1 mole, B.P. 168-9" C./l.2 mm., 12 1.6112) and anhydrouslithium cyanide (3.3 g., 0.1 mole, M.P. 161 C.) in 30 ml. of benzene.After refluxing overnight, the reaction mixture is filtered by nitrogenpressure into a distillation apparatus. A forerun of 5.6 g. of liquidobtained at 156159 C./l.2 mm. (m; 1.6090) is impure starting material:the undistillable brown-black residue, weighing 13.9 g., fusing in the60-70 C. range, is a polymer of cyanodiphenylphosphine oxide such astris(diphenylphosphinyl)triazine.

Aualysis.Calcd for C H NOP: C, 68.72; H. 4.44; N, 6.17; P, 13.63; 0,7.04. Found, percent: C, 67.18; H, 4.86; N, 5.83; P, 13.52, (by diff),8.61.

Example 8 This example illustrates preparation of anotherorganophosphorus cyanide polymer.

Following a procedure as described in Example 2,(pphenoxyphenyl)phenylphosphinothioic cyanide is subjected to a pressureof 7500 atmospheres at 275 C. for two hours. A quantitative yield (6.7g) of a jet-black condensation product with M.P. about 75 C. isrecovered from the lead capsule. This dissolves completely in warmbenzene (50 ml.). Addition of petroleum ether to the cooled benzenesolution precipitates a dark brown solid (3.4 g. after filtering anddrying). This fraction melts at 120130 C. A molecular weightdetermination by the freezing point depression of benzene gives a valueof 1635; since the monomer has a molecular weight of 335, the degree ofpolymerization is about 4.9.

For the preparation of (p-phenoxyphenyl)phenylphosphinothioic cyanide(cyano(phenoxyphenyl) phenylphosphine sulfide), 100 g. ofp-phenoxyphenylphosphonous dichloride is heated wiht 50 g. ofdiphenylmercury at 210- 215 C., under nitrogen, for 4 hours. The cooledreaction mixture is triturated with ligroin, filtered, and distilled torecover (p-phenoxyphenyl)phenylphosphinous chloride, B. 162-4/0.07 mm.,11 1.6472. Overnight reflux of 31 g. of the stated chloride with 15 g.of AgCN in 125 ml. of anhydrous benzene is followed by decanting thesupernatant layer and distilling to recover(p-phenoxyphenyl)phenylphosphinous cyanide, B. 16870 C./ 0.05 mm., 111.6353. Heating 43 g. of the stated cyanide with 26 g. of phosphorusthiochloride at 1400 C. until PCl evolution ceases and distillation ofthe residue yields cyano(p-phenoxyphenyl)phenylphosphine sulfide, B.174-6 C./0.02 mm., n 1.6576.

For production of a polynitrilomethylidyne polymer such as a triazinewith mixed phosphorus-containing substituents, a mixture ofcyano(p-phenoxyphenyl)phenylphosphine sulfide and cyanodiphenylphosphinesulfide is heated under pressure as desrcibed in Example 2.

While the invention has been described with specific reference toparticular preferred embodiments thereof, it will be appreciated thatmodification and variation can be made within the scope of the appendedclaims without departing from the invention, which is limited only asdefined n the appended claims.

What is claimed is:

1. The method of converting an organophosphorus cyanide to a polymercontaining repeating units of the same empirical formula as the initialmonomer which comprises contacting anhydrous lithium cyanide in anorganic solvent with an organophosphorus cyanide of the formula in whichR is an organic radical consisting of elements selected from the classconsisting of C, H and 0, said 0 being ether oxygen, linking adjoining Catoms, free of aliphatic unsaturation and containing up to 12 carbonatoms and up to 1 oxygen atom, X is a chalkogen element with an atomicweight below 35, a and b are the integers 1 or 2 and the sum of a and bis 3, and c is the integer 0 or 1.

2. The method of producing a poly(nitrilomethylidyne) containingorganoboryl substituents which comprises heating and compressing amixture of an organoboron cyanide of the formula (R) 'B(CEN) in which aand b are integers each with a value of at least 1, and the sum of a andb is 3, and an organophosphorus cyanide of the formula (R),,P(=X) (CEN)in which X is a chalkogen element with an atomic weight below 35,

a and b are the integers 1 or 2 and the sum of a and b is 3, c is theinteger 0 or 1, each R is an organic radical consisting of elementsselected from the class consisting of C, H and 0, said 0 being etheroxygen, linking adjoining C atoms, free of aliphatic unsaturation andcontaining up to 12 carbon atoms and up to 1 oxygen atom; provided thatat least 5 mole-percent of said mixture of cyanides is anorganophosphorus cyanide of said formula; at a pressure above about 1000kg./sq. cm. and a temperature above about 200 C.

3. The method of producing a polymeric product contair'iingorganophosphino and organoboryl substituents which comprises compressingand heating a mixture of cyanodiphenylborane and cyanodiphenylphosphineat a temperature above about 200 C. and a pressure above about 1000kg./sq. cm.; provided that at least 5 molepercent of said mixture iscyanodiphenylphosphine.

4. The method of producing a polymeric product containingorganophosphinothioyl and organoboryl substituents which comprisescompressing and heating a mixture of cyanodiphenylborane andcyanodiphenylphosphine sulfide at a temperature above about 200 C. and apressure above about 1000 kg./sq. cm. provided that at least 5molepercent of said mixture is cyanodiphenylphosphine sulfide.

5. The method of producing a polymeric product containing organosilylsubstitutents which comprises compressing and heating a mixture of anorganosilane cyanide of the formula (R) -Si(Cr-=N) in which a" and b"are integers with a value of at least 1, the sum of which is 4, and anorganophosphorus cyanide of the formula (R),.,P(=X) (C N) in which X isa chalkogen element with an atomic weight of at least 35, a and b arethe integers 1 or 2 and the sum of a and b is 3, c is the integer 0 or1, and each R is an organic radical consisting of elements selected fromthe class containing of C, H and 0, said 0 being ether oxygen, linkingadjoining C atoms, free of aliphatic unsaturation and containing up to12 carbon atoms and up to 1 oxygen atom; provided that at least 5mole-percent of said mixture is an organophosphorus cyanide of saidformula; to a temperature of above about 200 C. and a pressure of aboveabout 1000 kg./sq. cm.

6. The method of producing a polymeric product containingorganophosphinothioyl and organosilyl substituents, which comprisesheating and compressing a mixture of dicyanodiphenylsilane andcyanodiphenylphosphine sulfide at a temperature of above about 200 C.and a pressure of above about 1000 kg./sq. cm.; provided that at least 5mole-percent of said mixture is cyanodiphenylphosphine sulfide.

7. Tris(diorganophosphinothioyl)triazines in which the organic radicalsare aromatic radicals which each consist of elements selected from theclass consisting of C, H and 0, said 0 being ether oxygen, linkingadjoining C atoms, contain up to 12 aromatic carbon atoms and up to 1oxygen atom and are free of aliphatic unsaturation.

8. Tris(diphenylphosphinothioyl)triazine.

9. A poly(nitrilomethylidyne) having dihydrocarbylphosphino anddihydrocarbylboryl substituents in which each hydrocarbon radicalcontains up to 12 carbon atoms and is free of aliphatic unsaturation;provided that at least 5 mole-percent of said substituents aredihydrocarbylphosphino subsituents.

10. A poly(nitrilomethylidyne) having diphenylphosphino anddiphenylboryl substituents; provided that at least 5 mole-percent ofsaid substituents are diphenylphosphino substituents.

11. A poly(nitrilomethylidyne) having diphenylphosphinothioyl anddiphenylboryl substituents; provided that at least 5 mole-percent ofsaid substituents ar diphenylphosphinothioyl substituents.

12. A poly(nitrilomethylidyne) having a diphenylsilyl anddiphenylphosphinothioyl substituent; provided that 13 14 at least 5mole-percent of said substituents are diphenyl- OTHER REFERENCESPhosphmothloyl substmlents- Bengelsdorf: Journal American ChemicalSociety,

vol. 80 (1958), pp. 1442-4. References Clted Cairns et al.: JournalAmerican Chemical Society, UNITED STATES PATENTS 5 vol. 74 (1952), pp.5633-6. 3,165,513 1/1965 DAlehio 260 243 Hewertson et aL: Journal of theChemical Society,

L 1963, 670-5. FOREIGN PATENTS March pp 1 937,167 9/ 1963 Great Britain,SAMUEL H. BLECH, Primary Examiner.

1. THE METHOD OF CONVERTING AN ORGANOPHOSPHORUS CYANIDE TO A POLYMER CONTAINING REPEATING UNITS OF THE SAME EMPIRICAL FORMULA AS THE INITIAL MONOMER WHICH COMPRISES CONTACTING ANHYDROUS LITHIUM CYANIDE IN AN ORGANIC SOLVENT WITH AN ORGANOPHOSPHORUS CYANIDE OF THE FORMULA
 7. TRIS (DIORGANOPHOSPHINOTHIOYL) TRIAZINES IN WHICH THE ORGANIC RADICALS ARE AROMATIC RADICALS WHICH EACH CONSIST OF ELEMENTS SELECTED FROM THE CLASS CONSISTING OF C, H AND O, SAID O BEING ETHER OXYGEN, LINKING ADJOINING C ATOMS, CONTAIN UP TO 12 AROMATIC CARBON ATOMS AND UP TO 1 OXYGEN ATOM AND ARE FREE OF ALIPHATIC UNSATURATION. 